1. Field of the Invention
This invention relates to disposable respirators more particularly of the fold-flat type.
2. Description of the Prior Art
It is important to seek the protection of one's respiratory system with a respirator when subjected to unpleasant or noxious environments. However, respirator wearing comfort, convenience of carrying and freedom from maintenance are paramount to overcoming the commonly encountered resistance to use.
In addition to a further desire for compactness, lightness of weight and comfort of face fit, a wearer's ready acceptance of a particular respirator design requires minimal resistance to breathing through the face piece and avoidance of heretofore encountered "hot and clammy" breathing atmosphere within the face piece. This, in turn, requires adequate spacing of the face piece around nose and mouth and avoidance of collapse during inhalation.
Heretofore, the above has been best attended to with rigidly cupped and/or frame supported respirator structures of types exemplified by U.S. Pat. Nos. Des. 248,497 and 3,521,630. These, however, suffer the disadvantages of costly manufacture, ungainliness in storage and carrying by workers as well as a vulnerability to damage by crushing, particularly in the case of the type of structure illustrated in U.S. Pat. No. Des. 248,497. Frame supported structures, on the other hand, require periodic cleaning of the support structure, tedious filter replacement and provision for clean storage of the devices between times of use.
In view of the above, the more easily carried fold-flat type disposable pocket respirator is attractive to workers and suppliers alike. However, such devices, of which those of U.K. Pat. No. 1,588,442 and U.S. Pat. Nos. Des. 249,072 and 4,248,220 are exemplary, lack the ease of application to the face and conformity to the face provided by the more conventional rigid cup-formed and frame-supported devices. The ability to conform to the shape of the face provides both comfort and a good seal with the face, around the periphery of the respirator. In particular, the device of U.K. Pat. No. 1,588,442 has a horizontal seam which terminates in corners which contact the face in a manner detrimental both to comfort and to the objective of forming a good seal of the respirator against the face. Additionally, complicated pleating, stitching, riveting and other assembly procedures needed to produce prior art folded respirators render them relatively difficult and costly to produce.
Further, there exists a need in the art for a comfortable, disposable respirator having the ability to absorb toxic gases and vapors. Heretofore, relatively bulky respirators carrying a cartridge of some type have been employed for this purpose.
In view of the foregoing, an objective of the present invention is to provide improvements in fold-flat type respirators and method of making same.
Another object is to provide for simple and economical mass production of the respirators, more particularly by use of a continuous multi-ply layered web of disposable materials.
Still another object is to provide an end product offering exceptional face-fitting and breathing comfort with optimum air filtering efficiency.
Yet another object of the present invention is to provide a comfortable, fold-flat, disposable respirator having the capability of absorbing a toxic gas or vapor.
Other objects and advantages of the invention will become apparent from the following description when taken in conjunction with the accompanying drawings.